Apparatus for webpage scoring

ABSTRACT

A computer-implemented method, apparatus, and computer program product for evaluating a page in a website are provided. The method includes obtaining a link structure of the website. The method also includes identifying a page set, the page set being a set of pages linked to a specific page in the website. The method further includes calculating a degree of dispersion of the page set in the link structure. The method also includes evaluating the specific page using the degree of dispersion to generate a score for the specific page.

BACKGROUND

The present invention relates to webpage scoring.

The world wide web (WWW) has grown into a large useful database due tothe popularization of the Internet. Many people use web search enginesto obtain information efficiently. The web search-engines assign a scoreto a webpage according to its importance. As a result, users can findgood pages quickly from a great number of pages on the Internet

SUMMARY

According to an embodiment of the present invention, there is provided acomputer-implemented method for evaluating a page in a website. Themethod includes obtaining a link structure of the website. The methodfurther includes identifying a page set, the page set being a set ofpages linked to a specific page in the website. The method furtherincludes calculating a degree of dispersion of the page set in the linkstructure. The method further includes evaluating the specific pageusing the degree of dispersion.

According to another embodiment of the present invention, there isprovided an evaluating apparatus for evaluating a page in a website. Theevaluating apparatus for evaluating a page in a website includes anobtaining unit, an identifying unit, a calculating unit, and evaluatingunit. The obtaining unit is configured to obtain a link structure of thewebsite. The identifying unit is configured to identify a page set, thepage set being a set of pages linked to a specific page in the website.The calculating unit is configured to calculate a degree of dispersionof the page set in the link structure. The evaluating unit is configuredto evaluate the specific page using the degree of dispersion.

According to yet another embodiment of the present invention, there isprovided a computer program product for evaluating a page in a website.The computer program product includes a computer readable storage mediumhaving program instructions embodied therewith. The program instructionsare executable by a computer to cause the computer to perform theaforementioned method.

These and other features and advantages will become apparent from thefollowing detailed description of illustrative embodiments thereof,which is to be read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description will provide details of preferred embodimentswith reference to the following figures wherein:

FIG. 1 depicts a block diagram showing a configuration of a serveraccording to an exemplary embodiment of the present invention.

FIG. 2 is a flowchart of an operation of the server according to theexemplary embodiment.

FIG. 3A depicts a DAG representing a link structure of the first subjectwebsite according to the exemplary embodiment.

FIG. 3B depicts a DAG representing a link structure of the secondsubject website according to the exemplary embodiment.

FIG. 4 depicts a DAG representing a link structure of the third subjectweb site according to an alternative exemplary embodiment.

FIG. 5 depicts an example of a hardware configuration of the serveraccording to the exemplary embodiments.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present invention will bedescribed in detail with reference to the attached drawings.

It is to be noted that the present invention is not limited to theseexemplary embodiments to be given below and may be implemented withvarious modifications within the scope of the present invention. Inaddition, the drawings used herein are for purposes of illustration, andmay not show actual dimensions.

FIG. 1 depicts a block diagram showing a configuration of a server 100according to an exemplary embodiment of the present invention.

The server 100 shown in FIG. 1 is configured to score a webpage(s)(hereinafter referred to as a page(s)) in a local website (hereinafterreferred to as a subject website) for evaluating the respective pages.The server 100 may include an obtaining unit 110 for obtaining astructure of the subject website, a detecting unit 120 for detectinglinkage of the pages in the subject website, a calculating unit 130 forcalculating a degree of dispersion based on the linkage, and anevaluating unit 140 for evaluating the pages in the subject websitebased on the degree of dispersion. The degree of dispersion will beexplained later. The detecting unit 120 is an example of the claimedidentifying unit.

The obtaining unit 110 obtains a link structure of the subject websitefrom directories of the subject website. Here, the pages in the subjectwebsite can be organized with the directories as a hierarchicalstructure, so that the link structure of the subject website may beregarded as a graph. More specifically, the link structure (hereinafterreferred to as a structure G) may be shown as a shortest-path tree or adirected acyclic graph (DAG) that is obtained by a breadth-first searchfrom the top page of the subject website using the directories of thesubject website.

Note that the graph of the subject website includes nodes and edges(described later). The nodes correspond to respective pages in thesubject website. Assuming that the graph is a tree, the root in the treecorresponds to the top page of the subject website, and subtrees formcategories of the contents. The edges of the tree correspond torespective links between the pages.

Here, the obtaining unit 110 may obtain the graph by receivinginformation on the directories of the subject website via a network suchas the Internet, a local area network, a wide area network and awireless network.

The detecting unit 120 detects the linkage of the pages by identifying apage set Pt. The page set Pt is a set, i.e. a group of pages linked to atarget page Tp in the subject website. The target page Tp refers to apage to be evaluated. The target page Tp is an example of the claimedspecific page.

The detecting unit 120 identifies the page set Pt based on the structureG obtained by the obtaining unit 110. Note that since all pages includedin the subject website are typically required to be evaluated, thedetecting unit 120 identifies the page set Pt for every page included inthe subject website. The page set Pt will be explained below.

The calculating unit 130 calculates a degree of linkage regarding thetarget page Tp. More specifically, the calculating unit 130 calculates adegree of dispersion of the pages included in the page set Pt. In thepresent exemplary embodiment, this degree of dispersion in the structureG (hereinafter referred to as a div(Pt)) is calculated based on distancebetween a pair of subject nodes corresponding to a pair of pages in thepage set Pt in the graph. The div(Pt) will be explained later.

The evaluating unit 140 evaluates the respective pages in the subjectwebsite based on the div(Pt) calculated by the calculating unit 130. Toevaluate the pages, the evaluating unit 140 calculates scores of therespective pages based on the div(Pt). More specifically, the evaluatingunit 140 gives a high score to an entry (a page) having a high div(Pt).That is to say, the div(Pt) represents a degree of importance of thetarget page Tp. As shown in the figure, the evaluating unit 140 outputsa result of the evaluation via the network.

FIG. 2 is a flowchart of an operation of the server 100 according to theexemplary embodiment. Referring to FIGS. 1 and 2, the operation of theserver 100 will be explained.

The obtaining unit 110 first obtains the link structure G of the subjectwebsite from the directories of the subject website via the network(step 201). The detecting unit 120 then detects the linkage byidentifying the page set Pt of the target page Tp in the subject website(step 202). The calculating unit 130 then calculates the div(Pt) (step203). The evaluating unit 140 then evaluates the respective pages in thesubject website based on the div(Pt) (step 204). The evaluating unit 140then outputs the result of the evaluation via the network (step 205).

FIG. 3A depicts a DAG D1 representing a link structure of the firstsubject website according to the exemplary embodiment. FIG. 3B depicts aDAG D2 representing a link structure of the second subject websiteaccording to the exemplary embodiment. Referring to FIGS. 1, 3A and 3B,the calculation of the div(Pt) will be explained.

As mentioned above, the div(Pt) is calculated based on the distancebetween a pair of subject nodes (hereinafter referred to as nodes Pi,Pj) in the page set Pt. In the shown example, the distance of the nodesPi, Pj (hereinafter referred to as dist(Pi, Pj)) is determined byidentifying a lowest common ancestor (hereinafter referred to as lca(Pi,Pj)) of the nodes Pi, Pj. The lca(Pi, Pj) is the lowest, i.e. deepestnode that has both of the nodes Pi, Pj as its descendants in the DAG.The dist(Pi, Pj) is calculated as a sum of the distance between thelca(Pi, Pj) and the node Pi, and the distance between the lca(Pi, Pj)and the node Pj. The dist(Pi, Pj) is calculated for all pairs of nodesPi, Pj

The div(Pt) can be expressed as:

div(Pt)=Σ_(for all pairs of (Pi, Pj))dist(Pi,Pj)/Number of pairs

where (Pi, Pj) is the node Pi, Pj, and Number of pairs is a number ofpairs in the page set Pt.

Here, Number of pairs can be expressed as:

Number of pairs=|Pt|(|Pt|−1)/2

where ‘Pt’ is a number of pages included in the page set Pt.

Note that the div(Pt) is an example of the claimed average of distancebetween a pair of nodes corresponding to pages in the page set via alowest common ancestor of the pair of nodes.

As shown in FIG. 3A, the DAG D1 includes nodes P1 to P10 and directededges connecting the nodes P1 to P10. The nodes P1 to P10 correspond tothe respective pages of the first subject website. The node P1corresponds to the top page of the first subject website. Note that theedges correspond to hyperlinks.

Here, assuming that the page corresponding to the node P7 is the targetpage Pt, an example of the calculation of the div(Pt) will be explained.As shown in FIG. 3A, the node P7 is linked from the nodes P2, P6, P8,P9, and P10, so that the page set Pt will be a group of the pagescorresponding to the nodes P2, P6, P8, P9, and P10. Node 7 is not linkedfrom nodes P1, P3, P4, and P5.

Further, taking the nodes P6 and P8 as an example of the nodes Pi, Pj(the pair of subject nodes), lca(P6, P8) will be the node P1. Thus, thedist(P6, P8) is a sum of the distance between the node P1 and the nodeP6, and the distance between the node P1 and the node P8.

Here, the distance corresponds to a number of edges in a path betweenthe nodes in the graph. Two edges, i.e. edges E1 and E2, exist betweenthe node P1 and the node P6. Further, two edges, i.e. edges E3 and E4,exist between the node P1 and the node P8. Thus, the dist(P6, P8) isfour (4=2+2). The div(P7) is gained by calculating the other pairs inthe page set Pt, i.e. the group of the nodes P2, P6, P8, P9, and P10according to the above mentioned formula.

Similarly, the DAG D2 shown in FIG. 3B includes nodes P11 to P20 anddirected edges connecting the nodes P11 to P20. The nodes P11 to P20correspond to the respective pages of the second subject website.Further, the node P11 corresponds to the top page of the second subjectwebsite.

Here, another example of the calculation of the div(Pt) will beexplained assuming that the page corresponding to the node P20 is thetarget page Tp. As shown in FIG. 3B, the node P20 is linked from thenodes P14, P16, P17, P18, and P19, so that the page set Pt will be agroup of the pages corresponding to the nodes P14, P16, P17, P18, andP19. Node 20 is not linked from nodes P11, P12, P13, and P15.

Further, taking the nodes P16 and P17 as an example of the nodes Pi, Pj,lca(P16, P17) will be the node P14. Thus, the dist(P16, P17) is a sum ofthe distance between the node P14 and the node P16, and the distancebetween the node P14 and the node P17.

Here, one edge, i.e. edge E11, exists between the node P14 and the nodeP16, and one edge, i.e. edge E12, exists between the node P14 and thenode P17. Thus, the dist(P16, P17) is two (2=1+1). The dist(P16, P17) issmaller than the above mentioned dist(P6, P8). Similarly, other dist(Pi,Pj) as to the node P20 tends to be smaller than dist(Pi, Pj) as to thenode P7. Therefore, the div(P20) will be smaller than the div(P7).

Note that each of the node P7 and the node P20 is linked from fivenodes. However, the page corresponding to the node P7 seems to be moreimportant than the page corresponding to the node P20. This is becausethe page corresponding to the node P7 is linked from various pagescompared to the page corresponding to the node P20. In other words, thenode P7 is linked from the nodes located far from the node P7 comparedto the node 20. In the example, the div(P7) is larger than the div(P20),so that the score of the page corresponding to the node P7 will behigher than the page corresponding to the node P20.

In the present exemplary embodiment, the evaluation using the div(Pt)can reduce the effect of a dense link structure. The dense linkstructure refers to a link structure having a target node linked from agroup of nodes gathered in a specific area. If multiple links aredensely gathered in a group of pages showing the same topic, the denselink structure will be formed. For example, the link structure of thenode P20 is a dense link structure compared to the link structure of thenode P7.

In the example shown in the figures, the score of the page correspondingto the node P20 will be lower than the page corresponding to the node 7.Thus, the evaluation of the page corresponding to the node P20 with thedense link structure becomes low.

In a typical website, webpages have backlinks to the top page orancestors of the subject page (hereinafter referred to top pages), sothat the top pages are typically linked from many pages. That is to say,the top pages may have a dense structure in the typical website.

As a comparative example different from the present exemplaryembodiment, a comparative evaluation method will be explained. In thiscomparative evaluation method, the target page Tp is evaluated by anumber of links (incoming links) to the target page Tp. With thiscomparative evaluation method, the top pages tend to gain a high score.However, the top pages typically show general information, which isoften different from information a user searches for. Further, thecomparative evaluation method may overlook important pages located inleaves or their neighbors in the tree (the DAG). In contrast, thepresent exemplary embodiment can give low scores to the top pages, andgive high scores to the pages that seem to be important, i.e. popularentries mentioned in the subject website. The scores can be used toenhance and improve search results for a user searching for informationfound on a page deeper in the link structure of a website.

FIG. 4 depicts a DAG D3 representing a link structure of the thirdsubject website according to an alternative exemplary embodiment.Referring to FIG. 4, an alternative exemplary embodiment of the presentinvention will be explained.

In the above exemplary embodiment, the distance is determined by anumber of edges between the nodes Pi, Pj in the page set Pt. Thedistance is not limited to this. For example, the distance may bedetermined by a number of edges between a subject node corresponding toa page in the page set Pt and the node corresponding to the target pageTp. In other words, the target page Tp itself is used to determine thedistance in this alternative exemplary embodiment.

As shown in FIG. 4, the DAG D3 includes nodes P31 to P40 and directededges connecting the nodes P31 to P40. The nodes P31 to P40 correspondto the respective pages of the third subject website. Here, the pagecorresponding to the node P37 is assumed to be the target page Tp.Further, the page set Pt will be a group of the pages corresponding tothe nodes P32, P36, P38, P39, and P40. Nodes P31, P33, P34, and P35 arenot in the page set Pt.

Here, taking the node P36 as an example of the subject node, thedistance is determined by a number of edges between the node 36 and thenode 37. The lca(P36, P37) will be the node P32. The dist(P36, P37) is asum of the distance between the node P36 and the node P32, and thedistance between the node P37 and the node P32. The edge E31 existsbetween the node P36 and the node P32. The edge E32 exists between thenode P37 and the node P32. Thus, the dist(P36, P37) is two (2=1+1).

Similarly, taking the node P38 as another example of the subject node,the distance is determined by a number of edges between the node 37 andthe node 38. The lca(P37, P38) will be the node P31. The dist(P37, P38)is a sum of the distance between the node P37 and the node P31, and thedistance between the node P38 and the node P31. The edges E32 and E33exist between the node P37 and the node P31. The edges E34 and E35 existbetween the node P38 and the node P31. Thus, the dist(P37, P38) is four(4=2+2).

Here, instead of the lca(Pi, Pj), the distance can be determined with apredetermined node in the graph. For example, a central node may be usedto determine the distance. The central node is one node included in thegraph, and is in the closest position at an average distance from therespective nodes.

In the above exemplary embodiments, the scoring method utilizes only thelink structure regardless of the text included in the respective pages.However, the above mentioned scoring method can utilize both of the linkstructure and the text. In other words, the above mentioned scoringmethod can be used with other scoring methods, such as text search. Forexample, the score gained by the above mentioned scoring method can beused to adjust the result of the text search.

In the above exemplary embodiments, a high score is given to the pagehaving a high div(Pt). As long as the score of the target page Tp isbased on the div(Pt), a manner of scoring is not limited to this. Forexample, a low score can be given to the page having a high div(Pt).

The pages of the local website are not limited to an actual webpage. Forexample, an object included in the webpage, such as an image, may betreated as a page (a subpage). In this case, a node corresponding to thesubpage (the image) is included in the graph.

Referring to FIG. 5, there is shown an example of a hardwareconfiguration of the sever 100 in the exemplary embodiments. As shown inthe figure, the server 100 may include a central processing unit (CPU)91, a main memory 92 connected to the CPU 91 via a motherboard (M/B)chip set 93, and a display driver 94 connected to the CPU 91 via thesame M/B chip set 93. The display driver 94 can cause a display to showa user a customized search results page using the score obtained fromthe evaluation unit 140. The customized search results page using thescore to improve the results for the user to display the websites withthe information searched for instead of the comparative method. Anetwork interface 96, a magnetic disk device 97, an audio driver 98, anda keyboard/mouse 99 are also connected to the M/B chip set 93 via abridge circuit 95.

In FIG. 5, the various configurational elements are connected via buses.For example, the CPU 91 and the M/B chip set 93, and the M/B chip set 93and the main memory 92 are connected via CPU buses, respectively. Also,the M/B chip set 93 and the display driver 94 may be connected via anaccelerated graphics port (AGP). However, when the display driver 94includes a PCI express-compatible video card, the M/B chip set 93 andthe video card are connected via a PCI express (PCIe) bus. Also, whenthe network interface 96 is connected to the bridge circuit 95, a PCIExpress may be used for the connection, for example. For connecting themagnetic disk device 97 to the bridge circuit 95, a serial AT attachment(ATA), a parallel-transmission ATA, or peripheral componentsinterconnect (PCI) may be used. For connecting the keyboard/mouse 99 tothe bridge circuit 95, a universal serial bus (USB) may be used.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Smalltalk, C++ or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the describedembodiments. The terminology used herein was chosen to best explain theprinciples of the embodiments, the practical application or technicalimprovement over technologies found in the marketplace, or to enableothers of ordinary skill in the art to understand the embodimentsdisclosed herein.

What is claimed is:
 1. A computer-implemented method for evaluating apage in a website, comprising: obtaining a link structure of thewebsite; identifying a page set, the page set being a set of pageslinked to a specific page in the website; calculating a degree ofdispersion of the page set in the link structure; evaluating thespecific page using the degree of dispersion to generate a scoreindicating a relative importance for the specific page; and displayingcustomized search results based on the generated score.
 2. Thecomputer-implemented method according to claim 1, wherein the specificpage of which the degree of dispersion is higher is evaluated morehighly.
 3. The computer-implemented method according to claim 1, whereinthe link structure of the website is a directed acyclic graph (DAG). 4.The computer-implemented method according to claim 1, wherein the degreeof dispersion is calculated based on distance in the link structurebetween a pair of nodes corresponding to pages in the page set.
 5. Thecomputer-implemented method according to claim 1, wherein the degree ofdispersion is calculated based on a number of edges in a path between apair of nodes corresponding to pages in the page set via another node inthe link structure.
 6. The computer-implemented method according toclaim 1, wherein the degree of dispersion is calculated based on anaverage of distance between a pair of nodes corresponding to pages inthe page set via a lowest common ancestor of the pair of nodes.
 7. Thecomputer-implemented method according to claim 1, further comprisingdetermining a distance using a predetermined node in a graph.
 8. Anevaluating apparatus for evaluating a page in a website, comprising: anobtaining unit configured to obtain a link structure of the web site; anidentifying unit configured to identify a page set, the page set being aset of pages linked to a specific page in the website; a calculatingunit configured to calculate a degree of dispersion of the page set inthe link structure; an evaluating unit configured to evaluate thespecific page using the degree of dispersion to generate a scoreindicating a relative importance for the specific page; and a displayunit configured to display customized search results based on thegenerated score.
 9. The evaluating apparatus according to claim 8,wherein the specific page of which the degree of dispersion is higher isevaluated more highly.
 10. The evaluating apparatus according to claim8, wherein the link structure of the website is a directed acyclic graph(DAG).
 11. The evaluating apparatus according to claim 8, wherein thedegree of dispersion is calculated based on distance in the linkstructure between a pair of nodes corresponding to pages in the pageset.
 12. The evaluating apparatus according to claim 8, wherein thedegree of dispersion is calculated based on a number of edges in a pathbetween a pair of nodes corresponding to pages in the page set viaanother node in the link structure.
 13. The evaluating apparatusaccording to claim 8, wherein the degree of dispersion is calculatedbased on an average of distance between a pair of nodes corresponding topages in the page set via a lowest common ancestor of the pair of nodes.14. A computer program product for evaluating a page in a website, thecomputer program product comprising a computer readable storage mediumhaving program instructions embodied therewith, the program instructionsexecutable by a computer to cause the computer to: obtain a linkstructure of the web site; identify a page set, the page set being a setof pages linked to a specific page in the website; calculate a degree ofdispersion of the page set in the link structure; evaluate the specificpage using the degree of dispersion to generate a score indicating arelative importance for the specific page; and displaying customizedsearch results based on the generated score.
 15. The computer programproduct according to claim 14, wherein the specific page of which thedegree of dispersion is higher is evaluated more highly.
 16. Thecomputer program product according to claim 14, wherein the linkstructure of the website is a directed acyclic graph (DAG).
 17. Thecomputer program product according to claim 14, wherein the degree ofdispersion is calculated based on distance in the link structure betweena pair of nodes corresponding to pages in the page set.
 18. The computerprogram product according to claim 14, wherein the degree of dispersionis calculated based on a number of edges in a path between a pair ofnodes corresponding to pages in the page set via another node in thelink structure.
 19. The computer program product according to claim 14,wherein the degree of dispersion is calculated based on an average ofdistance between a pair of nodes corresponding to pages in the page setvia a lowest common ancestor of the pair of nodes.
 20. The computerprogram product according to claim 14, further comprising determining adistance using a predetermined node in a graph.